Turbine assemblies may include, without limitation, turbine sections of steam turbines and compressor and/or turbine sections of gas turbines. A steam turbine has a steam path which typically includes a steam inlet, a turbine and a steam outlet. A gas turbine has a gas path which typically includes an air intake (or inlet), a compressor, a combustor, a turbine and a gas outlet (or exhaust nozzle). Gas or steam leakage, either out of the gas or steam path or into the gas or steam path, from an area of higher pressure to an area of lower pressure is generally undesirable. For example, gas-path leakage in the turbine or compressor area of a gas turbine, between the rotor of the turbine or compressor and the circumferentially surrounding turbine or compressor casing, will lower the efficiency of the gas turbine leading to increased fuel costs. Additionally, gas-path leakage in the combustor section of a gas turbine will require an increase in bum temperature to maintain the power level, with such increased burn temperatures leading to increased emissions, such as increased NOx production. Further, steam-path leakage in the turbine area of a steam turbine, between the rotor of the turbine and the circumferentially surrounding casing, will lower the efficiency of the steam turbine leading to increased fuel costs.
Turbine seals are typically used to minimize the leakage of fluids in a turbine assembly. As is generally known, side or spline seals may often be utilized for sealing gaps between adjacent turbine components. For example, elongated metallic cloth seals are known for sealing the sides between adjacent turbine components, such as circumferentially-adjacent transition pieces. However, such seals are typically pressure loaded only, relying primarily on high pressure fluids, such as compressor discharge air, contacting a high pressure side of the turbine seal to maintain the seal in sealing engagement with the adjacent turbine components. With regard to pressure loaded seals, it has been found that there can be significant leakage between the sealed turbine components when the seal becomes warped and/or gaps develop between the seal and the corners of the turbine components. Moreover, current pressure loaded turbine seals often become unseated from and/or fail to conform to the sealing surfaces of the adjacent turbine components, thereby permitting further leakage between the components.
Accordingly, a seal assembly that minimizes the potential for leakage between adjacent turbine components would be welcomed in the technology.